In order to supply electrical power to devices which rotate or revolve relative to the source of power, it is a common practice to provide an arrangement of brushes and contact rings, known as slip rings, in continuous mutual sliding contact. Either the brushes or rings may rotate while the others are stationary. When such an arrangement is employed on a large rotating structure, such as a large agricultural center pivot irrigation sprinkler of the type disclosed in U.S. Pat. No. 3,659,627, great difficulties arise as it becomes necessary to replace the rings because of wear, since the water supply for such a sprinkler system generally passes through the axis of the rings. It is often necessary to substantially dismantle the structure in order to make repairs since the slip rings in such rotary junction devices are often continuous. Such dismantling can be complex, time consuming and therefore expensive.